A femtosecond laser direct writing device with online detection function and its usage method

Abstract

This application provides a femtosecond laser direct writing device with online detection capability and its usage method, relating to the field of laser precision processing and detection technology. By integrating a laser direct writing module, a microscopic imaging module, and a three-dimensional imaging module into an optical system, the femtosecond laser direct writing device achieves efficient and accurate online detection capabilities.

Description

Technical Field

[0001] This application relates to the field of laser precision processing and testing technology, and more specifically, to a femtosecond laser direct writing device and method with online testing function. Background Technology

[0002] With advancements in laser processing equipment and high-power femtosecond lasers, the processing efficiency and online inspection accuracy of ultra-precision laser direct writing equipment and similar products have significantly improved, also raising the technical threshold for laser direct writing equipment. However, the online inspection accuracy and efficiency of existing equipment have become bottlenecks in the production process. In particular, most online inspection scenarios rely on offline inspection, severely impacting processing efficiency and quality. Therefore, designing a dedicated online optical system to ensure efficient laser transmission to the processing area of ​​the workpiece, meeting the requirements of high-precision micro-nano processing and online automatic inspection accuracy, thereby improving the automation level of laser direct writing, is crucial.

[0003] There is currently no effective technical solution to the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a femtosecond laser direct writing device and its usage method with online detection function. By integrating a laser direct writing module, a microscopic imaging module and a three-dimensional imaging module into an optical system, the femtosecond laser direct writing device achieves efficient and accurate online detection function.

[0005] This application provides a femtosecond laser direct writing device with online detection function, including: an electronic control system and an optical system. The optical system includes a laser direct writing module, a microscopic imaging module, a three-dimensional imaging module, a first dichroic mirror, a second dichroic mirror, a laser objective, a Mirau-type interference objective, an imaging objective, and an objective linear switching platform.

[0006] The laser direct writing module is used to emit a femtosecond laser, which passes through a first dichroic mirror, a second dichroic mirror and a laser objective lens in sequence to process the workpiece;

[0007] The three-dimensional imaging module is used to emit a continuous spectrum beam, and the continuous spectrum beam is split into a reference beam and a measurement beam by the Mirau-type interferometer objective. The three-dimensional imaging module is also used to acquire a three-dimensional image of the workpiece based on the returned reference beam and measurement beam.

[0008] The microscopic imaging module is used to sequentially emit bright field illumination light and dark field illumination light to irradiate the workpiece and form bright field reflected light and dark field reflected light. The microscopic imaging module is also used to generate bright field images and dark field images based on the returned bright field reflected light and dark field reflected light, respectively.

[0009] The laser objective, the Mirau-type interference objective, and the imaging objective are all mounted on the objective linear switching platform. The objective linear switching platform is used to switch the position of each objective so that one of the objectives is in the working position.

[0010] The electronic control system is used to generate online detection results based on the bright field image, the dark field image and the three-dimensional image, and to optimize processing parameters based on the online detection results. The electronic control system is also used to control the laser direct writing module to process the workpiece.

[0011] The above settings enable efficient and accurate online detection for the femtosecond laser direct writing device.

[0012] Optionally, the optical system further includes a focusing platform connected to the objective lens linear switching platform. The microscopic imaging module is equipped with a focusing sensor, which emits a detection laser. The detection laser is focused onto the workpiece surface by the laser objective lens, the Mirau-type interferometer objective lens, or the imaging objective lens, and then reflected and returns along the original path to the focusing sensor. The focusing sensor is also used to output the height information of the focusing focal plane based on the returned detection laser. The focusing platform is used to adjust the height of the objective lens linear switching platform according to the height information, so that the focusing focal plane of the laser objective lens, the Mirau-type interferometer objective lens, or the imaging objective lens is located on the workpiece surface.

[0013] The above settings ensure that the laser objective lens is accurately focused on the workpiece surface and guarantee the accuracy of two-dimensional and three-dimensional imaging.

[0014] Optionally, the microscopic imaging module includes an illumination module, a third dichroic mirror, a first beam splitter, an imaging tube, and a color camera. The illumination module emits bright-field illumination light, which is transmitted through the third dichroic mirror and the first beam splitter, then reflected by the second dichroic mirror, and passes through the imaging objective to illuminate the workpiece, forming bright-field reflected light. The bright-field reflected light is reflected by the second dichroic mirror and the first beam splitter and enters the imaging tube for combined imaging to generate a bright-field image by the color camera. The illumination module also emits dark-field illumination light, which is transmitted through the third dichroic mirror and the first beam splitter, then reflected by the second dichroic mirror, and passes through the imaging objective to illuminate the workpiece, forming dark-field reflected light. The dark-field reflected light is reflected by the second dichroic mirror and the first beam splitter and enters the imaging tube for combined imaging to generate a dark-field image by the color camera. The objective linear switching platform is used to align the imaging objective with the second dichroic mirror.

[0015] Through the collaborative work of these components, the microscopic imaging module can effectively acquire bright-field and dark-field images of the workpiece processing area, providing an image data foundation for subsequent online inspection and processing parameter optimization.

[0016] Optionally, the illumination module includes a bright-field illumination component, a dark-field illumination component, a reflector, and a second beam splitter. The bright-field illumination component is used to emit bright-field illumination light, which is reflected by the reflector and the second beam splitter to the third dichroic mirror. The dark-field illumination component is used to emit dark-field illumination light, which is transmitted through the second beam splitter to the third dichroic mirror.

[0017] Optionally, both the bright-field illumination component and the dark-field illumination component include a red LED, a red collimating lens, a green LED, a green collimating lens, a blue LED, a blue collimating lens, and a three-primary-color combining prism. The red LED, the green LED, and the blue LED are all used to emit light sources and pass through their respective collimating lenses. The three-primary-color combining prism is used to combine the light sources emitted by the red LED, the green LED, and the blue LED into the bright-field illumination light or the dark-field illumination light.

[0018] Optionally, the three-dimensional imaging module includes an SLD light source, a second collimating mirror, a polarizing beam splitter, a quarter-wave plate, a three-dimensional imaging tube mirror, an analyzer, a three-dimensional camera, and a piezoelectric ceramic phase shifter. The SLD light source emits the continuous spectrum beam, which is collimated by the second collimating mirror and then incident on the polarizing beam splitter. The polarizing beam splitter outputs linearly polarized light, which is converted into circularly polarized light by the quarter-wave plate. The circularly polarized light is reflected by the first dichroic mirror, passes through the second dichroic mirror, and enters the Mirau-type interference objective. The Mirau-type interference objective splits the light into a reference beam and a measurement beam. The measurement beam is reflected by the workpiece and returns to the Mirau-type interference objective. The U-shaped interference objective, together with the reference beam, passes through the second dichroic mirror for transmission and the first dichroic mirror for reflection, and then is converted into linearly polarized light by a quarter-wave plate. The linearly polarized light is reflected by the polarizing beam splitter and enters the three-dimensional imaging tube and the analyzer to form interference fringes. The piezoelectric ceramic phase shifter is connected to the Mirau-type interference objective and the objective linear switching platform, respectively. The piezoelectric ceramic phase shifter is used to adjust the interference phase shift of the Mirau-type interference objective. The three-dimensional camera is used to generate a three-dimensional image based on the interference fringes and the interference phase shift. The objective linear switching platform is used to align the Mirau-type interference objective with the second dichroic mirror.

[0019] Optionally, the laser direct writing module includes a femtosecond laser, an automatic attenuator, a two-dimensional scanning galvanometer group, an F-θ field mirror, and a laser tube mirror. The femtosecond laser is used to emit femtosecond laser light. After passing through the automatic attenuator, the femtosecond laser light is transmitted to the F-θ field mirror through the two-dimensional scanning galvanometer group to form a focused spot. The focused spot is scaled by the laser tube mirror and then passes sequentially through a first dichroic mirror, a second dichroic mirror, and a laser objective lens to process the workpiece. The automatic attenuator has a built-in mechanical shutter that can shut off the laser. The objective lens linear switching platform is used to align the laser objective lens with the second dichroic mirror.

[0020] Optionally, the laser direct writing module further includes a continuously zooming lens, which is used to convert the femtosecond laser into a circular flat-top spot with a corresponding magnification according to different magnifications.

[0021] Optionally, the electronic control system includes a moving workpiece stage, a fixed frame, an electronic control unit, and a computer. The fixed frame is disposed on the moving workpiece stage and is used to mount the optical system. The electronic control unit is connected to the computer, and is connected to both the optical system and the moving workpiece stage. The moving workpiece stage is used to place the workpiece to be processed. The electronic control unit is used to control the operation of the optical system and the moving workpiece stage. The computer is used to control the automated operation of the optical system and the moving workpiece stage.

[0022] Secondly, this application provides a method of using a femtosecond laser direct writing device with online detection function. Based on the femtosecond laser direct writing device with online detection function described in any of the preceding claims, the method of using the femtosecond laser direct writing device with online detection function includes the following steps:

[0023] The electronic control system acquires the processing parameters of the workpiece to be processed, and controls the laser direct writing module to process the workpiece according to the processing parameters;

[0024] After the direct writing process is completed, the electronic control system controls the laser direct writing module to turn off the laser to switch to online detection mode;

[0025] In the online detection mode, the electronic control system controls the operation of the microscopic imaging module and the three-dimensional imaging module to obtain the bright field image, the dark field image and the three-dimensional image;

[0026] The electronic control system performs data fusion processing based on the bright field image, the dark field image, and the three-dimensional image to obtain online detection results;

[0027] The electronic control system is also used to optimize the processing parameters of the laser direct writing module based on the online detection results.

[0028] As can be seen from the above, the femtosecond laser direct writing device and its usage method with online detection function provided in this application realize the efficient and accurate online detection function of the femtosecond laser direct writing device through an optical system that integrates a laser direct writing module, a microscopic imaging module and a three-dimensional imaging module.

[0029] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing embodiments of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the femtosecond laser direct writing device with online detection function provided in the embodiments of this application.

[0031] Figure 2 This is a schematic diagram of the structure of the microscopic imaging module provided in an embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the structure of the three-dimensional imaging module provided in an embodiment of this application.

[0033] Figure 4 This is a schematic diagram of the structure of the bright field lighting component provided in the embodiments of this application.

[0034] Figure 5 This is a schematic diagram of the structure of the electronic control system provided in the embodiments of this application.

[0035] Labeling Explanation: 100, Laser Direct Writing Module; 200, Microscopic Imaging Module; 300, 3D Imaging Module; 1, Femtosecond Laser; 2, Automatic Attenuator; 3, Continuous Zoom Lens; 4, Two-Dimensional Scanning Galvanometer Group; 5, F-θ Field Lens; 6, Laser Tube Lens; 7, First Dichroic Mirror; 8, Second Dichroic Mirror; 9, Focusing Platform; 10, Objective Lens Linear Switching Platform; 11, Laser Objective; 12, Mirau-type Interference Objective; 13, Imaging Objective; 14, Piezoelectric Ceramic Phase Shifter; 15, First Beam Splitter; 16, Third Dichroic Mirror; 17, Color Camera; 18, Imaging Tube Lens; 19, Focusing Sensor; 400, Illumination Module; 201 101. Bright field illumination assembly; 202. Dark field illumination assembly; 203. Reflector; 204. Second beam splitter; 211. Red LED; 212. Red collimating lens; 213. Green LED; 214. Green collimating lens; 215. Blue LED; 216. Blue collimating lens; 217. Tri-color combining prism; 101. SLD light source; 102. Second collimating lens; 103. Polarizing beam splitter; 104. Quarter wave plate; 105. 3D imaging tube lens; 106. Analyzer; 107. 3D camera; 500. Optical system; 501. Moving workpiece stage; 502. Fixture; 503. Electrical control unit; 504. Computer. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] Please refer to Figure 1-Figure 5 , Figure 1This is a schematic diagram of the overall structure of a femtosecond laser direct writing device with online inspection function provided in this application. It is designed to solve the problem of inefficient and inaccurate online inspection in femtosecond laser direct writing processes. The device integrates a laser direct writing module 100, a microscopic imaging module 200, and a three-dimensional imaging module 300 into an optical system 500, thus combining processing and inspection.

[0039] In a first aspect, this application provides a femtosecond laser direct writing device with online detection function, including: an electronic control system and an optical system 500. The optical system 500 includes a laser direct writing module 100, a microscopic imaging module 200, a three-dimensional imaging module 300, a first dichroic mirror 7, a second dichroic mirror 8, a laser objective lens 11, a Mirau-type interference objective lens 12, an imaging objective lens 13, and an objective lens linear switching platform 10.

[0040] The laser direct writing module 100 is used to emit a femtosecond laser, which passes through the first dichroic mirror 7, the second dichroic mirror 8 and the laser objective lens 11 in sequence to process the workpiece;

[0041] The three-dimensional imaging module 300 is used to emit a continuous spectrum beam, which is reflected by the first dichroic mirror 7 and then passes through the second dichroic mirror 8 into the Mirau-type interferometer objective 12. The Mirau-type interferometer objective 12 splits the beam into a reference beam and a measurement beam. The measurement beam is reflected by the workpiece and returns to the Mirau-type interferometer objective 12, and then returns to the three-dimensional imaging module 300 along the same path as the reference beam. The three-dimensional imaging module 300 is also used to acquire a three-dimensional image of the workpiece based on the returned reference beam and measurement beam.

[0042] The microscopic imaging module 200 is used to sequentially emit bright-field illumination light and dark-field illumination light, so that the corresponding illumination light is reflected by the second dichroic mirror 8 and passes through the imaging objective lens 13 to illuminate the workpiece to form bright-field reflected light and dark-field reflected light. The reflected light returns to the microscopic imaging module 200 along the original path. The microscopic imaging module 200 is also used to generate bright-field images and dark-field images based on the returned bright-field reflected light and dark-field reflected light.

[0043] The laser objective 11, the Mirau-type interference objective 12, and the imaging objective 13 are all mounted on the objective linear switching platform 10. The objective linear switching platform 10 is used to switch the positions of each objective so that one of the objectives is in the working position (for example, the objective linear switching platform 10 aligns the imaging objective 13 with the second dichroic mirror 8, the objective linear switching platform 10 aligns the Mirau-type interference objective 12 with the second dichroic mirror 8, or the objective linear switching platform 10 aligns the laser objective 11 with the second dichroic mirror 8, thereby enabling the operation of each module).

[0044] The electronic control system is used to generate online detection results based on bright field images, dark field images, and three-dimensional images, and to optimize processing parameters based on the online detection results. The electronic control system is also used to control the laser direct writing module 100 to process the workpiece.

[0045] Specifically, the laser direct writing module 100 emits a femtosecond laser, which passes through a first dichroic mirror 7, a second dichroic mirror 8, and a laser objective lens 11 to perform micro-nano processing on the workpiece. To achieve online detection of the processed area, the optical system 500 also includes a microscopic imaging module 200 and a three-dimensional imaging module 300. The microscopic imaging module 200 emits bright-field and dark-field illumination light. The illumination light passes through the second dichroic mirror 8 and the imaging objective lens 13 to illuminate the workpiece. The reflected light returns to the microscopic imaging module 200, generating bright-field and dark-field images of the workpiece's processed area for two-dimensional topography detection. The three-dimensional imaging module 300 emits a continuous spectrum beam. The beam is reflected by the first dichroic mirror 7, then by the second dichroic mirror 8 and a Mirau-type interference objective lens 12. Within the Mirau-type interference objective lens 12, the beam is split into a reference beam and a measurement beam. The measurement beam, after being reflected by the workpiece, returns to the three-dimensional imaging module 300 along with the reference beam, generating a three-dimensional image of the workpiece's processed area for three-dimensional topography detection.

[0046] The laser objective 11, the Mirau-type interference objective 12, and the imaging objective 13 are mounted on the objective linear switching platform 10. This platform allows different objectives to be positioned in their working positions, enabling rapid switching between laser processing objectives and online inspection objectives. Online inspection can be performed without moving the workpiece, thus improving inspection efficiency. The electronic control system receives images generated by the microscopic imaging module 200 and the three-dimensional imaging module 300, performs data fusion processing to obtain online inspection results, and optimizes laser processing parameters based on these results. This achieves closed-loop control of the processing process, improving processing accuracy and quality.

[0047] The first dichroic mirror 7 and the second dichroic mirror 8 serve as optical beam combiners / splitters, integrating the laser direct writing optical path, the microscopic imaging optical path, and the three-dimensional imaging optical path into the same optical system 500, simplifying the system structure. The introduction of the microscopic imaging module 200 and the three-dimensional imaging module 300 enables the device to perform bright-field and dark-field two-dimensional imaging and three-dimensional topography detection, achieving multi-dimensional online detection of the processing area. The objective lens linear switching platform 10 enables rapid switching between processing and inspection objectives, ensuring efficient online detection. The electronic control system optimizes processing parameters based on the detection results, achieving closed-loop control of the processing process. In summary, this technical solution, through the coordinated work of various modules, achieves efficient and accurate online detection functions for the femtosecond laser direct writing device.

[0048] In some embodiments, the optical system 500 further includes a focusing platform 9 connected to the objective lens linear switching platform 10. The microscopic imaging module 200 is equipped with a focusing sensor 19, which is used to emit a detection laser. The detection laser is focused onto the workpiece surface by the laser objective lens 11, the Mirau-type interference objective lens 12, or the imaging objective lens 13, and then reflected and returns along the original path to the focusing sensor 19. The focusing sensor 19 is also used to output the height information of the focusing focal plane based on the returned detection laser. The focusing platform 9 is used to adjust the height of the objective lens linear switching platform 10 according to the height information so that the focusing focal plane of the laser objective lens 11, the Mirau-type interference objective lens 12, or the imaging objective lens 13 is located on the workpiece surface.

[0049] Specifically, the focusing platform 9 enables synchronized adjustment of the height of all objectives on the linear objective switching platform 10. The introduction of the focusing sensor 19 provides height information to the focusing platform 9, enabling automatic focusing. By detecting feedback from the laser and height information, the system can automatically adjust the objective height, ensuring that the laser objective 11, the Mirau-type interferometer objective 12, and the imaging objective 13 are accurately focused on the workpiece surface during switching. This automatic focusing mechanism reduces the need for manual adjustment, improving operational efficiency and processing accuracy.

[0050] The focusing sensor 19 can be a laser displacement sensor that emits a detection laser with a wavelength of visible or infrared light. The focusing platform 9 can be an electrically operated lifting platform that uses a servo motor and a lead screw structure to adjust the height of the objective lens linear switching platform 10. The electronic control system receives the height information output by the focusing sensor 19 and adjusts the height of the objective lens linear switching platform 10 with an adjustment accuracy down to the micrometer or even nanometer level. For example, before fine processing in a femtosecond laser direct writing device, automatic focusing is first performed using the focusing sensor 19 and the focusing platform 9 to ensure that the laser objective lens 11 is accurately focused on the workpiece surface before laser processing is performed. When switching to the microscopic imaging module 200 and the three-dimensional imaging module 300 for online inspection, the height of the imaging objective lens 13 and the Mirau-type interferometer lens 12 can also be adjusted by focusing to ensure the accuracy of two-dimensional and three-dimensional imaging.

[0051] In some embodiments, the microscopic imaging module 200 includes an illumination module 400, a third dichroic mirror 16, a first beam splitter 15, an imaging tube lens 18, and a color camera 17. The illumination module 400 emits bright-field illumination light, which is transmitted through the third dichroic mirror 16 and the first beam splitter 15, then reflected by the second dichroic mirror 8, and passes through the imaging objective lens 13 to illuminate the workpiece, forming bright-field reflected light. The bright-field reflected light is reflected by the second dichroic mirror 8 and the first beam splitter 15 and enters the imaging tube lens 18 for combined imaging. The color camera 17 generates a bright-field image. The illumination module 400 is also used to emit dark-field illumination light. The dark-field illumination light is transmitted through the third dichroic mirror 16 and the first beam splitter 15, and then reflected by the second dichroic mirror 8 before passing through the imaging objective lens 13 to illuminate the workpiece and form dark-field reflected light. The dark-field reflected light is reflected by the second dichroic mirror 8 and the first beam splitter 15 and enters the imaging tube lens 18 for combined imaging to generate a dark-field image by the color camera 17. The objective lens linear switching platform 10 is used to align the imaging objective lens 13 with the second dichroic mirror 8. Figure 2 As shown.

[0052] Specifically, the illumination module 400 provides both bright-field and dark-field illumination sources to meet different imaging requirements. The third dichroic mirror 16 and the first beam splitter 15 work together to guide the light paths of the illumination and reflected light, ensuring effective illumination of the workpiece and guiding the reflected light to the imaging tube 18. The imaging tube 18 is used to image the reflected light, while the color camera 17 captures the image information. Through the coordinated operation of these components, the microscopic imaging module 200 can effectively acquire bright-field and dark-field images of the workpiece processing area, providing an image data foundation for subsequent online inspection and processing parameter optimization.

[0053] In some embodiments, the illumination module 400 includes a bright field illumination component 201, a dark field illumination component 202, a reflector 203, and a second beam splitter 204. The bright field illumination component 201 is used to emit bright field illumination light, which is reflected by the reflector 203 and the second beam splitter 204 to a third dichroic mirror 16. The dark field illumination component 202 is used to emit dark field illumination light, which is transmitted through the second beam splitter 204 to the third dichroic mirror 16.

[0054] Specifically, the bright-field illumination light emitted by the bright-field illumination component 201 first has its optical path direction changed by the reflector 203, and then reflected by the second beam splitter 204, aligning its optical path with that of the dark-field illumination light. The dark-field illumination light emitted by the dark-field illumination component 202 passes directly through the second beam splitter 204. In this way, utilizing the beam-splitting characteristics of the second beam splitter 204, the two different types of illumination light are spatially combined and uniformly guided into the subsequent optical element, the third dichroic mirror 16, providing a composite light source for subsequent microscopic imaging. This structural design allows the bright-field and dark-field illumination to be independently controlled and optimized, and then, through optical path integration, they share the subsequent optical path, simplifying the complexity of the optical system 500 and providing a hardware foundation for switching and coordinating the two illumination modes, bright-field and dark-field.

[0055] In some embodiments, both the bright-field illumination component 201 and the dark-field illumination component 202 include a red LED 211, a red collimating lens 212, a green LED 213, a green collimating lens 214, a blue LED 215, a blue collimating lens 216, and a tri-color combining prism 217. The red LED 211, green LED 213, and blue LED 215 emit light sources that pass through their respective collimating lenses. The tri-color combining prism 217 combines the light emitted by the red LED 211, green LED 213, and blue LED 215 into bright-field illumination light or dark-field illumination light, such as... Figure 4 As shown.

[0056] LED light sources are used as the light sources for both the bright-field illumination component 201 and the dark-field illumination component 202. For example, both the bright-field illumination component 201 and the dark-field illumination component 202 may include a red LED 211, a green LED 213, and a blue LED 215. The light emitted by these LED light sources is collimated by corresponding collimating lenses, and then the collimated red, green, and blue light is combined into illumination light by a tri-color combining prism 217. The third dichroic mirror 16 can be a film system with high reflectivity and high transmittance for light of a specific wavelength. For example, a dichroic mirror with high reflectivity for the excitation wavelength and high transmittance for the emission wavelength can be selected. The first beam splitter 15 can be a film-layer beam splitter, and the beam splitting ratio can be selected according to actual needs. For example, a beam splitter with a beam splitting ratio of 50:50 can be selected. The imaging tube lens 18 can be an achromatic lens group to reduce chromatic aberration and improve image quality. The color camera 17 can be a CMOS color camera, which features high resolution and high frame rate, and can quickly capture clear images. By selecting and configuring the above components, the microscopic imaging module 200 can achieve high-quality bright-field and dark-field microscopic imaging of the workpiece processing area, providing reliable data support for online inspection, and thus enabling real-time monitoring and optimization of the laser direct writing process.

[0057] In some embodiments, the three-dimensional imaging module 300 includes an SLD light source 101, a second collimating lens 102, a polarizing beam splitter 103, a quarter-wave plate 104, a three-dimensional imaging tube lens 105, an analyzer 106, a three-dimensional camera 107, and a piezoelectric ceramic phase shifter 14. The SLD light source 101 emits a continuous spectrum beam, which is collimated by the second collimating lens 102 and then incident on the polarizing beam splitter 103. The polarizing beam splitter 103 outputs linearly polarized light, which is converted into circularly polarized light by the quarter-wave plate 104. The circularly polarized light is reflected by the first dichroic mirror 7 and then passes through the second dichroic mirror 8 into the Mirau-type interferometer objective lens 12, where it is split into a reference beam and a measurement beam. The measurement beam is then processed by a... After reflection, the light returns to the Mirau-type interference objective 12 and, together with the reference beam, is transmitted through the second dichroic mirror 8 and reflected by the first dichroic mirror 7. It is then converted into linearly polarized light by the quarter-wave plate 104. The linearly polarized light is reflected by the polarizing beam splitter 103 and enters the three-dimensional imaging tube lens 105 and analyzer 106, forming interference fringes. The piezoelectric ceramic phase shifter 14 is connected to both the Mirau-type interference objective 12 and the objective linear switching platform 10. The piezoelectric ceramic phase shifter 14 is used to adjust the interference phase shift of the Mirau-type interference objective 12. The three-dimensional camera 107 is used to generate a three-dimensional image based on the interference fringes and interference phase shift. The objective linear switching platform 10 is used to align the Mirau-type interference objective 12 with the second dichroic mirror 8. Figure 3 As shown.

[0058] When the 3D imaging module 300 is working, the continuous spectrum beam emitted by the SLD light source 101 is collimated by the second collimating mirror 102 to form a parallel beam. The collimated continuous spectrum beam is incident on the polarizing beam splitter 103, which splits the beam into linearly polarized light. The linearly polarized light is converted into circularly polarized light after passing through the quarter-wave plate 104. The circularly polarized light is reflected by the first dichroic mirror 7, then passes through the second dichroic mirror 8, and enters the Mirau-type interference objective 12. The Mirau-type interference objective 12 splits the beam into a reference beam and a measurement beam. The measurement beam illuminates the workpiece surface and reflects back carrying the workpiece surface topography information, interfering with the reference beam. The interfered beam returns along the same path, is transmitted through the second dichroic mirror 8 and reflected by the first dichroic mirror 7, and then passes through the quarter-wave plate 104 again, where it is converted into linearly polarized light. The linearly polarized light is reflected by the polarizing beam splitter 103 and enters the 3D imaging tube lens 105 and the analyzer 106. The analyzer 106 is used to improve the contrast of the interference fringes, making them clearer. The 3D camera 107 acquires images containing the interference fringes. The piezoelectric ceramic phase shifter 14 precisely controls the position of the Mirau-type interference objective 12, adjusting the optical path difference between the reference beam and the measurement beam to achieve interference phase shift. Based on the acquired interference fringe images under different phase shifts, the 3D camera 107 calculates and generates a 3D image of the workpiece surface. By combining white light interferometry and polarization beam splitting techniques, the 3D imaging module 300 achieves a measurement resolution below the nanometer level, ensuring high-quality identification of key features of the processed sample, solving the problem of insufficient accuracy in online detection, and improving the accuracy and quality of online detection.

[0059] The SLD light source 101 can be a superluminescent diode with a center wavelength of 840nm to provide a broadband light source. The second collimating lens 102 is a lens with a focal length of 20mm to collimate and diverge the continuous spectrum beam. The polarizing beam splitter prism 103 is a prism with an extinction ratio greater than 1000:1 to ensure polarization beam splitting effect. The quarter-wave plate 104 is a wave plate with a working wavelength range covering the visible to near-infrared band. The Mirau-type interference objective 12 is an objective with a numerical aperture of 0.55, a magnification of 50X, and a working distance of 2mm. The piezoelectric ceramic phase shifter 14 can achieve a displacement resolution of 1nm, realizing nanometer-level phase shift control. The three-dimensional camera 107 is a CMOS camera with a resolution of 1280x1024 and a pixel size of 5.3μm. The above are only preferred embodiments of this application, and the model parameters can be set according to actual needs. No specific limitations are made here.

[0060] In some embodiments, the laser direct writing module 100 includes a femtosecond laser 1, an automatic attenuator 2, a two-dimensional scanning galvanometer group 4, an F-θ field lens 5, and a laser tube lens 6. The femtosecond laser 1 emits a femtosecond laser beam. After passing through the automatic attenuator 2, the femtosecond laser beam is transmitted through the two-dimensional scanning galvanometer group 4 to the F-θ field lens 5 to form a focused spot. The focused spot passes through the laser tube lens 6 and then sequentially through a first dichroic mirror 7, a second dichroic mirror 8, and a laser objective lens 11 before being scaled and sized to process the workpiece. The automatic attenuator 2 has a built-in mechanical shutter that can shut off the laser beam. The objective lens linear switching platform 10 is used to align the laser objective lens 11 with the second dichroic mirror 8. Figure 1 As shown.

[0061] Specifically, the working principle of the laser direct writing module 100 is as follows: First, the femtosecond laser 1 generates a high-energy femtosecond laser pulse; the laser pulse then enters the automatic attenuator 2, where the laser energy is precisely adjusted to adapt to the specific material and processing parameters; the energy-adjusted laser beam is incident on the two-dimensional scanning galvanometer group 4; under the control of the electronic control system, the two-dimensional scanning galvanometer group 4 precisely deflects the direction of the laser beam, realizing the two-dimensional scanning motion of the laser beam on the workpiece surface, scanning out the predetermined processing pattern; the scanned laser beam passes through the F-θ field lens 5, which focuses the scanned laser beam onto the workpiece surface and corrects aberrations during the scanning process, ensuring the quality and positional accuracy of the focal point; to further improve processing accuracy, before the laser beam reaches the workpiece surface, it also needs to undergo a relay scaling of the light spot through the combination of the laser tube lens 6 and the laser objective lens 11 (the relay scaling is achieved by focusing the light through the F-θ field lens 5). The laser spot is formed as a primary image, and then the laser tube lens 6 and laser objective lens 11 are combined to form a secondary image and transfer it to the workpiece, achieving microscopic-level reduction of the laser spot. The final spot size focused on the workpiece surface reaches the micrometer or even submicrometer level, meeting the needs of high-precision micro-nano processing. The automatic attenuator 2 integrates a mechanical shutter (the mechanical shutter has a response time of 0.1s) which can quickly shut off the laser (because the switching of the femtosecond laser 1 requires a certain amount of time to stabilize the power), facilitating subsequent switching of online detection modes and quickly avoiding unnecessary laser irradiation, which is crucial for the processing of fine patterns. Through the coordinated work of the above components, the laser direct writing module 100 can achieve precise control of laser energy, spot shape, and scanning trajectory. This high-precision laser direct writing capability provides high-quality processed samples for subsequent online detection, ensuring the accuracy and reliability of online detection results.

[0062] In some embodiments, the laser direct writing module 100 further includes a continuous zoom lens 3, which is used to convert the femtosecond laser into a circular flat-top spot of a corresponding magnification according to different magnifications.

[0063] Specifically, the femtosecond laser emitted by the femtosecond laser 1 enters the continuous zoom lens 3 after passing through the automatic attenuator 2. The continuous zoom lens 3 converts the femtosecond laser into a circular flat-top light spot with the corresponding magnification and outputs it to the two-dimensional scanning galvanometer group 4, and then transmits it to the F-θ field lens 5 to form a focused light spot.

[0064] Different applications require different laser spot sizes. The continuous zoom lens 3 solves this problem by allowing users to adjust the magnification and thus the spot size without changing the lens. By adjusting the zoom lens, the femtosecond laser beam can be shaped into a circular flat-top beam with the desired magnification. This allows for optimization of the laser spot size for different materials and processing parameters, thereby improving the processing flexibility and applicability of the laser direct writing device.

[0065] In some embodiments, the electronic control system includes a moving workpiece stage 501, a mounting frame 502, an electronic control unit 503, and a computer 504. The mounting frame 502 is disposed on the moving workpiece stage 501 and is used to mount the optical system 500. The electronic control unit 503 is connected to the computer 504, and is connected to both the optical system 500 and the moving workpiece stage 501. The moving workpiece stage 501 is used to place the workpiece to be processed. The electronic control unit 503 is used to control the operation of the optical system 500 and the moving workpiece stage 501. The computer 504 is used to control the automated operation of the optical system 500 and the moving workpiece stage 501. Figure 5 As shown.

[0066] The motion stage 501 is configured to carry the workpiece to be processed and provide precise positional movement capabilities to support workpiece positioning requirements during laser direct writing and online inspection. The mounting bracket 502 is designed as a support structure for mounting the optical system 500. By being mounted on the motion stage 501, it integrates the optical system 500 with the motion stage 501, ensuring the stability of the optical system 500 during movement. The electronic control unit 503, as the core control component, is responsible for receiving instructions from the computer 504 and converting them into control signals for the optical system 500 and the motion stage 501, coordinating the collaborative work of each component. The computer 504 serves as an advanced control platform, performing tasks such as image processing, data analysis, online inspection result generation, and automated workflow management. A communication connection is established between the computer 504 and the electronic control unit 503, enabling the transmission of control commands and data. The electronic control unit 503 is further connected to the optical system 500 and the motion stage 501, realizing precise control of hardware devices such as the femtosecond laser 1, the two-dimensional scanning galvanometer group 4, the objective lens linear switching platform 10, the color camera 17, the three-dimensional camera 107, and the motion stage 501.

[0067] When the electronic control system is working, the computer 504 first generates corresponding control commands based on preset processing parameters or online inspection requirements. These commands are sent to the electronic control unit 503. After parsing the commands, the electronic control unit 503 drives the moving workpiece stage 501 to move along a predetermined trajectory, while simultaneously controlling the laser direct writing module 100 to emit a laser beam to process the workpiece, or controlling the microscopic imaging module 200 and the three-dimensional imaging module 300 to acquire image data of the workpiece surface. In online inspection mode, the bright-field images, dark-field images, and three-dimensional images acquired by the microscopic imaging module 200 and the three-dimensional imaging module 300 are transmitted to the computer 504. The computer 504 performs fusion processing and analysis on these image data to generate online inspection results. The online inspection results can be used to evaluate the processing quality and fed back to the electronic control unit 503 for real-time adjustment and optimization of the processing parameters of the laser direct writing module 100. Through the coordinated operation of the moving workpiece stage 501, the fixed frame 502, the electronic control unit 503, and the computer 504, the automated control and online inspection functions of the femtosecond laser direct writing device are realized.

[0068] Secondly, this application provides a method for using a femtosecond laser direct writing device with online detection function. Based on any of the aforementioned femtosecond laser direct writing devices with online detection function, the method for using the femtosecond laser direct writing device with online detection function includes the following steps:

[0069] The electronic control system acquires the processing parameters of the workpiece to be processed, and controls the laser direct writing module 100 to process the workpiece according to the processing parameters;

[0070] After the direct writing process is completed, the electronic control system controls the laser direct writing module 100 to turn off the laser and switch to the online detection mode;

[0071] In online detection mode, the electronic control system controls the operation of the microscopic imaging module 200 and the three-dimensional imaging module 300 to obtain bright-field images, dark-field images and three-dimensional images;

[0072] The electronic control system performs data fusion processing based on bright-field images, dark-field images, and 3D images to obtain online detection results;

[0073] The electronic control system is also used to optimize the processing parameters of the laser direct writing module 100 based on the online detection results.

[0074] Among them, data fusion processing is an existing technology, such as multimodal feature extraction and fusion or deep learning-driven methods, but not limited to these.

[0075] Specifically, the electronic control system first acquires the processing parameters of the workpiece to be processed, and then controls the laser direct writing module 100 to process the workpiece according to the processing parameters. After the laser direct writing processing is completed, the electronic control system controls the laser direct writing module 100 to turn off the laser and switches to online detection mode. In online detection mode, the electronic control system controls the microscopic imaging module 200 and the three-dimensional imaging module 300 to work together to acquire bright field images, dark field images and three-dimensional images of the workpiece processing area. These images contain the surface morphology and quality information of the workpiece after processing. The electronic control system performs data fusion processing on these multi-source images and comprehensively analyzes them to obtain online detection results. More importantly, the electronic control system can optimize the processing parameters of the laser direct writing module 100 based on the online detection results. Thus, the processing process forms a closed-loop feedback electronic control system, realizing real-time online detection and parameter optimization of processing results. This overcomes the shortcomings of low efficiency and untimely feedback in traditional offline detection, and improves the automation, efficiency and processing quality of laser direct writing processing. By guiding the adjustment of subsequent processing parameters through online detection results, more accurate and high-quality laser direct writing processing can be achieved.

[0076] Specifically, the process begins with the operator setting or the system pre-setting processing parameters, which may include laser power, scanning speed, and pattern. The electronic control system then sends signals to the laser direct writing module 100, driving it to execute the manufacturing process according to these parameters. After the laser direct writing process is completed, the electronic control system stops the laser emission of the laser direct writing module 100 and switches the system to online inspection mode. This mode switch may involve the movement of physical components or simply a change in the system's operating mode. In online inspection mode, the electronic control system controls the microscopic imaging module 200 and the three-dimensional imaging module 300 to work together to capture images of the processed workpiece area. The microscopic imaging module 200 provides bright-field and dark-field images, while the three-dimensional imaging module 300 provides three-dimensional topographic images. After acquiring the images from the microscopic imaging module 200 and the three-dimensional imaging module 300, the electronic control system performs data fusion to obtain a comprehensive evaluation of the processing results. Based on the online inspection results, if the results show a deviation from the expected results, the system modifies the processing parameters (such as laser power and scanning speed) to improve subsequent processing cycles.

[0077] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0078] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A femtosecond laser direct writing device with online detection function, characterized in that, include: The electronic control system and the optical system (500) include a laser direct writing module (100), a microscopic imaging module (200), a three-dimensional imaging module (300), a first dichroic mirror (7), a second dichroic mirror (8), a laser objective (11), a Mirau-type interference objective (12), an imaging objective (13), and an objective linear switching platform (10). The laser direct writing module (100) is used to emit a femtosecond laser, which passes through the first dichroic mirror (7), the second dichroic mirror (8) and the laser objective (11) in sequence to process the workpiece; The three-dimensional imaging module (300) is used to emit a continuous spectrum beam, and the continuous spectrum beam is split into a reference beam and a measurement beam by the Mirau-type interferometer (12). The three-dimensional imaging module (300) is also used to acquire a three-dimensional image of the workpiece based on the returned reference beam and measurement beam. The microscopic imaging module (200) is used to sequentially emit bright field illumination light and dark field illumination light to irradiate the workpiece to form bright field reflected light and dark field reflected light. The microscopic imaging module (200) is also used to generate bright field image and dark field image respectively based on the returned bright field reflected light and dark field reflected light. The laser objective (11), the Mirau type interference objective (12) and the imaging objective (13) are all mounted on the objective linear switching platform (10). The objective linear switching platform (10) is used to switch the position of each objective so that one of the objectives is in the working position. The electronic control system is used to generate online detection results based on the bright field image, the dark field image and the three-dimensional image, and to optimize processing parameters based on the online detection results. The electronic control system is also used to control the laser direct writing module (100) to process the workpiece. The optical system (500) also includes a focusing platform (9), which is connected to the objective lens linear switching platform (10). The microscopic imaging module (200) is provided with a focusing sensor (19). The focusing sensor (19) is used to emit a detection laser. The detection laser is focused onto the workpiece surface by the laser objective lens (11), the Mirau type interference objective lens (12), or the imaging objective lens (13), and then reflected and returns along the original path to the focusing sensor (19). The focusing sensor (19) is also used to output the height information of the focusing focal plane according to the returned detection laser. The focusing platform (9) is used to adjust the height of the objective lens linear switching platform (10) according to the height information so that the focusing focal plane of the laser objective lens (11), the Mirau type interference objective lens (12), or the imaging objective lens (13) is located on the workpiece surface.

2. The femtosecond laser direct writing device with online detection function according to claim 1, characterized in that, The microscopic imaging module (200) includes an illumination module (400), a third dichroic mirror (16), a first beam splitter (15), an imaging tube (18), and a color camera (17). The illumination module (400) emits bright-field illumination light, which is transmitted through the third dichroic mirror (16) and the first beam splitter (15), then reflected by the second dichroic mirror (8), and passes through the imaging objective (13) to illuminate the workpiece, forming bright-field reflected light. The bright-field reflected light is reflected by the second dichroic mirror (8) and the first beam splitter (15) and enters the imaging tube (18) for combined imaging to be captured by the color camera. The machine (17) generates a bright field image. The illumination module (400) is also used to emit dark field illumination light. The dark field illumination light is transmitted through the third dichroic mirror (16) and the first beam splitter (15), and then reflected by the second dichroic mirror (8) and passes through the imaging objective (13) to illuminate the workpiece to form dark field reflected light. The dark field reflected light is reflected by the second dichroic mirror (8) and the first beam splitter (15) and enters the imaging tube lens (18) for combined imaging so that the color camera (17) generates a dark field image. The objective lens linear switching platform (10) is used to align the imaging objective (13) with the second dichroic mirror (8).

3. The femtosecond laser direct writing device with online detection function according to claim 2, characterized in that, The illumination module (400) includes a bright field illumination component (201), a dark field illumination component (202), a reflector (203), and a second beam splitter (204). The bright field illumination component (201) is used to emit bright field illumination light, which is reflected by the reflector (203) and the second beam splitter (204) to the third dichroic mirror (16). The dark field illumination component (202) is used to emit dark field illumination light, which is transmitted through the second beam splitter (204) to the third dichroic mirror (16).

4. The femtosecond laser direct writing device with online detection function according to claim 3, characterized in that, Both the bright field illumination component (201) and the dark field illumination component (202) include a red LED (211), a red collimating lens (212), a green LED (213), a green collimating lens (214), a blue LED (215), a blue collimating lens (216), and a three-primary-color combining prism (217). The red LED (211), the green LED (213), and the blue LED (215) are used to emit light sources and pass through their respective collimating lenses. The three-primary-color combining prism (217) is used to combine the light sources emitted by the red LED (211), the green LED (213), and the blue LED (215) into the bright field illumination light or the dark field illumination light.

5. The femtosecond laser direct writing device with online detection function according to claim 1, characterized in that, The three-dimensional imaging module (300) includes an SLD light source (101), a second collimating lens (102), a polarizing beam splitter (103), a quarter-wave plate (104), a three-dimensional imaging tube lens (105), an analyzer (106), a three-dimensional camera (107), and a piezoelectric ceramic phase shifter (14). The SLD light source (101) emits the continuous spectrum beam. The continuous spectrum beam is collimated by the second collimating lens (102) and then incident on the polarizing beam splitter (103). The polarizing beam splitter (103) outputs linearly polarized light, which is converted into circularly polarized light by the quarter-wave plate (104). The circularly polarized light is reflected by the first dichroic mirror (7) and then passes through the second dichroic mirror (8) into the Mirau-type interference objective (12). The Mirau-type interference objective (12) splits the light into a reference beam and a measurement beam. The measurement beam is reflected by the workpiece. The light returns to the Mirau-type interference objective (12) and, together with the reference beam, is transmitted through the second dichroic mirror (8) and reflected by the first dichroic mirror (7). It is then converted into linearly polarized light by a quarter-wave plate (104). The linearly polarized light is reflected by the polarizing beam splitter (103) and enters the three-dimensional imaging tube (105) and the analyzer (106) to form interference fringes. The piezoelectric ceramic phase shifter (14) is connected to the Mirau-type interference objective (12) and the objective linear switching platform (10) respectively. The piezoelectric ceramic phase shifter (14) is used to adjust the interference phase shift of the Mirau-type interference objective (12). The three-dimensional camera (107) is used to generate a three-dimensional image based on the interference fringes and the interference phase shift. The objective linear switching platform (10) is used to align the Mirau-type interference objective (12) with the second dichroic mirror (8).

6. The femtosecond laser direct writing device with online detection function according to claim 1, characterized in that, The laser direct writing module (100) includes a femtosecond laser (1), an automatic attenuator (2), a two-dimensional scanning galvanometer group (4), an F-θ field lens (5), and a laser tube lens (6). The femtosecond laser (1) is used to emit femtosecond laser. After passing through the automatic attenuator (2), the femtosecond laser is transmitted to the F-θ field lens (5) through the two-dimensional scanning galvanometer group (4) to form a focused spot. The focused spot is scaled by the laser tube lens (6) and then passes through the first dichroic mirror (7), the second dichroic mirror (8), and the laser objective lens (11) in sequence to process the workpiece. The automatic attenuator (2) has a built-in mechanical shutter, which can turn off the laser. The objective lens linear switching platform (10) is used to align the laser objective lens (11) with the second dichroic mirror (8).

7. The femtosecond laser direct writing device with online detection function according to claim 1, characterized in that, The laser direct writing module (100) also includes a continuous zoom lens (3), which is used to convert the femtosecond laser into a circular flat-top spot of the corresponding magnification according to different magnifications.

8. The femtosecond laser direct writing device with online detection function according to claim 1, characterized in that, The electronic control system includes a moving workpiece stage (501), a fixing frame (502), an electronic control unit (503), and a computer (504). The fixing frame (502) is mounted on the moving workpiece stage (501) and is used to mount the optical system (500). The electronic control unit (503) is connected to the computer (504). The electronic control unit (503) is connected to the optical system (500) and the moving workpiece stage (501). The moving workpiece stage (501) is used to place the workpiece to be processed. The electronic control unit (503) is used to control the operation of the optical system (500) and the moving workpiece stage (501). The computer (504) is used to control the automated operation of the optical system (500) and the moving workpiece stage (501).

9. A method of using a femtosecond laser direct writing device with online detection function, characterized in that, The femtosecond laser direct writing device with online detection function according to any one of claims 1-8, the method of using the femtosecond laser direct writing device with online detection function includes the following steps: The electronic control system acquires the processing parameters of the workpiece to be processed, and the electronic control system controls the laser direct writing module (100) to process the workpiece according to the processing parameters; After the direct writing process is completed, the electronic control system controls the laser direct writing module (100) to turn off the laser to switch to the online detection mode; In the online detection mode, the electronic control system controls the operation of the microscopic imaging module (200) and the three-dimensional imaging module (300) to obtain the bright field image, the dark field image and the three-dimensional image; The electronic control system performs data fusion processing based on the bright field image, the dark field image, and the three-dimensional image to obtain online detection results; The electronic control system is also used to optimize the processing parameters of the laser direct writing module (100) based on the online detection results.

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